Welding power supplies or systems are available for a wide variety of processes, and with a wide variety of sophistication. Welding-type power supply or system, as used herein, includes power supplies or systems that provide welding, cutting or heating power, and may include a controller, switches, etc. Traditionally, a good weld required an experienced welder, not only to properly execute the weld, but to properly select operating parameters (such. as output voltage, current, power, pulse width, wire feed speed, etc.)
Now, robots are available that execute the weld. Also, operating parameters may be pre-determined and automatically implemented by a controller in the weding-type power supply. The automation is typically a software program that describes the output waveform, and is executed by a digital processor (microprocessors, DSPs, etc.). The program attempts to implement and improve upon the decisions that had been made by the experienced welder.
The programs and waveforms are “hard-coded”, where a computer program includes typical control loops and procedures, such as “if-then, “go-to”, etc. For example, a decision would be on the order of: “if the pulse phase has timed out and we are not in a short circuit and the trigger is still pulled then go to the background phase” (written, of course, in a computer language such as “C”).
While how to write such a program is well known, it can be very difficult to modify such a program. Modification requires a review of each line of code, which is then carefully modified to give the desired result. Modification can, of course, cause unexpected consequences or require re-writing of entire sections. Such changes may be extremely time consuming, requires the person doing the modification to understand the software language and understand the particular interaction of all the hard coded lines in the system. Also, with each change, software bugs may be introduced and the program can require extensive trouble-shooting.
Welding automation is becoming increasingly sophisticated. This requires increasingly sophisticated control software, which only exacerbates the difficulty in updating or modifying a welding program. For example, a weld process might include peak amps, background amps, and a first ramp for the transition from background to peak. As the process control becomes more sophisticated, a second ramp from peak to background might be added, or the first ramp might be broken into two section with different slopes. It requires a substantial re-writing of the hard code to include these waveform segments. Then, if additional changes are made later, the code must be written again. Each addition to the code can lengthen the code, and make subsequent changes even more difficult.
Accordingly, a method and apparatus for controlling a welding-type power supply that allows for changing the waveform without requiring a lengthy and difficult re-writing of a program is desirable.